This document discusses different ways to describe sets. It defines sets using roster notation by listing elements within curly braces separated by commas. Elements can be denoted by small letters and membership is shown using the symbol ∈. The cardinality operator n(A) represents the number of elements in a set. Sets can also be described verbally or using set-builder notation, which lists the characteristic that determines if an object is a member.

2. Dear God,
May we,
through your blessings,
add purity to the world
subtract evil from our lives,
multiply your good news
and divide your gifts and
share them with others
Amen!

3. 3

4. Gadget Collection

5. A set of Sports Ball

6. A Flock of Birds

7. A Family of Plants

8. A Set of Utensils

9. is described as a well- defined collection of objects
is usually denoted by CAPITAL LETTERS

11. Element or Member

12.  Objects of a set and is denoted by small letters
 Elements are enclosed by braces and separated by
commas.
Element or Member

13. More example:
* If set A contains the letters a, b, c, d, and e, then we write
the set as :
* Set B consisting of the elements 5, 10, 15, and 20.
A= {a, b, c, d, e}
B= {5, 10, 15, 20}

14.  Used to indicate that an object is an element or a
member of the set.
Examples:
∈
 Indicate that an object is NOT an element of the set
∉
A= { a, b, c, d, e}
b ∈ A which is read as “b is an element of set A” or “b belongs to
set A”
h ∉ A which is read as “h is not an element of set A”.

15.  number of elements in a given set
Cardinality

16. 1. A= { a, b, c, d, e}
n(A)= 5
2. F= { 1,2,3,4}
n(F)= 4
3. G= { }
n(G)= 0
Cardinality
More example:

18. Roster
Method
 It is the method of
describing a set by listing each
element of the set inside the
symbol { }.
Examples:
1. A= { 1, 2, 3, 4}
NOTE:
In listing the elements of the set, each
distinct element is listed once and the order of
the elements does not matter.
Philippines
2. B = { f, a, t}
P= { p, h, i, l, n, e, s}

19. Verbal
Description
Method
 It is a method of describing
a set into words.
Examples:
1. Set A is the set of counting
numbers less than 5.
3. Set C is the set of distinct letters
in the word “Philippines”.
2. Set B is the set of letters in the
word “fat”.

20. Set- Builder
Notation
 It is a method that lists the
rules that determine whether an
object is an element of the set rather
than the actual elements.
Examples:
1. A= {x l x is a counting number less
than 5}
NOTE:
The vertical line “ l “ is read as “ such
that ” .
* “the set of all x such that x is a counting
number less than 5.”
2. B= {x l x is a letter in the word “fat” }
3. C= {x l x is a distinct letter in the word
“Philippines” }